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My 73 Stingray passenger low beam light goes out when the light door is fully open. The light is on until after halfway open and go off the high beam works only not the low beam function of the bulb. I have replaced the both bulbs the high beam bulb works fine. I have confirmed the connection is clean and tight. The bracket assembly is loose compared to the drivers side. Any ideas on a solution?
I looked on the wiring schematic for the 73 headlights. The high and low beams use the same ground. It sounds like the cable/wire has gone bad, and it might be helpful to turn the low beams on, while powered up, use your hand to move/disturb the cable. Your next step will be to use a volt meter to ascertain that power is going to the low beam, you can unplug the cable and see where the power is lost.
I have confirmed power to the bulb as it works when the lights first open but goes out when fully open which is very odd. The light stays on until about three quarter open.
Any help greatly appreciated my son and I are at a loss for why this is occurring.
Since the wires are 47 years old, you can be sure that there are no wear spots, or places were the copper has broken. Try and feel the wire/cable to
see if you can get the bulb to come on, albeit for a moment. I am betting the copper is frayed inside the jacket, you could use straight pins pushed into each cable 12 inches or so before the plug to see if there is 12 volts present. This method avoids cutting the jacket, be sure and don’t allow the pins to touch each other or any metal!
Good idea with the pins I have confirmed that power is present at the bulb socket when fully open. The bulb works and goes out when fully open. Moving the wire enabled the bulb to work when open but isn’t sustainable.
The problem is an intermittent break in one of the conductors. If both cables are bundled together, it will probably be easier to replace both wires.
NAPA has a good selection of wire, you can use single conductor (16 GA), tape together, cut out the bad section, use heat shrink and solder the new wires to the old cable. You will most likely encounter corrosion on the main cable, use find sandpaper to clean the copper so it can be soldered.
Thanks for the video. Obviously there is an intermittent open in the circuit that goes to your Passenger Side Low Beam Bulb. On my 73 wiring schematic, three wires go to the Low Beam Connector. One is a 16 GA. Black, a 16 Ga. Tan, a 16 Ga. Lt. Green. Remove the high Low Beam Bulb and inspect the connector looking at those three wires. I will bet you a cup of coffee that your problem is with the Tan wire. The Other two wires go on to the High Beam (that comes on), Black & LT. Green Passenger side Low Beam bulb is on the left
. Turn on the Low Beams, be gentle and move/adjust the three cables while they are attached to the Low Beam Bulb. MOVE Quickly as the BULB will GET HOT. You could get lucky, and just need to reinsert the TAN wire into the Low Beam Connector.
Thanks so much for taking the time and effort to respond with great detail to my post the extremely help I will try your suggestions and let all know how it works out.
The vette belonged to my father in-law and me and my son are excited about the restoration.
Glad to help. It would be wise to obtain a 1973 Chevrolet Factory Service Manual along with the 1973 AIM (Assembly Instruction Manual) if you plan on doing any repairs yourself. The books are available on eBay and not very expensive. From the look of your video, your vacuum (makes the headlights go and down) is not very strong. When they get worse, just Google the subject or post the problem on the Forum. Enjoy your 1973, they are a transitional year, paint front bumper, chrome rear bumper.
I just replaced all my engine, front lamp and dash harness and I was having this issue. Went back and found out I didn’t tighten the ground bolt on the alternator. After tightening that my problems went away.
You confirmed there is voltage present but you probably still have a bad wire. It is twisted and there are 20 wires twisted together and 15 could be broken. Load from light will not stay on with few wires. Meter will read. You know your bulbs are good. ie you can put 12 volts on them and they light? I would run a wire tan from the dimmer switch to the low beam at light and see if problem goes away.
you still have hot to bulb when fully open? then the ground wire is the problem. don't waste your time messing with it. just run another ground. the bar glued to the hood surround that the rear of headlights attach to. it has horns bolted to it, and they don't have separate grounds. so that bracket needs to be grounded to the frame.
1973 Headlight goes out
